This invention relates in general to vehicle wheel hubs and vehicle brake rotors and in particular to an improved structure for such a vehicle wheel hub and brake rotor and method for producing the same.
It is known to cast a rotatable brake component (e.g., a rotor or drum) with an integral hub portion. A conventional integral hub and rotor includes an axially extending hub, a radially extending mounting surface, and a radially extending outer disc which can be integrally cast of the same material as one-piece during a casting operation. The hub includes a centrally located bore formed therein, and a plurality of equally spaced lug bolt receiving holes are formed in the mounting surface circumferentially about the bore. The outer disc defines a pair of brake friction plates having opposed braking surfaces which are typically machined to be parallel to one another and perpendicular to the rotor axis. The integral hub and rotor defines an inner bearing seat for receiving a bearing unit, such as for example, a preassembled cartridge type of bearing unit. The cartridge bearing unit can either be a pregreased sealed-for-life cartridge bearing, or of the type having a pair of bearing elements, either ball bearings or tapered roller bearings, disposed between an inner bearing race or cup and an outer bearing race or cup.
U.S. Pat. No. 5,988,324 to Bertetti et al. discloses a wheel hub bearing unit of a two-piece design. As disclosed the Bertetti et al. patent, the wheel hub bearing unit includes a bearing flange member which is secured to a flange of a disc or drum member by a suitable cold forming process (e.g., punching, pinching, rolling).
This invention relates to a vehicle wheel hub and brake rotor including a wheel hub portion formed from a first material and a brake rotor portion formed from a second material and joined to the wheel hub flange during an in situ casting process. The method for producing the vehicle wheel hub and brake rotor of the present invention includes the steps of (a) providing wheel hub portion formed from a first material and including a radially outwardly extending wheel hub flange; (b) placing the wheel hub portion in a mold; and (c) casting a brake rotor portion formed from a second material in situ therewith, the brake rotor portion including a flange which is operatively joined to the wheel hub flange during the in situ casting process to thereby join the wheel hub portion to the brake rotor portion.
Other advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiments, when read in light of the accompanying drawings.